[Prognostic significance of ventricular echo beats induced during programmed ventricular stimulation (author's...

To determine the incidence and prognostic significance of the repetitive ventricular response, the present retrospective study was done in 123 patients (75 male, 48 female, mean age +/- S.D. 49 +/- 14 years) with a variety of cardiac rhythm disorders. Programmed right ventricular stimulation was done at a basic pacing rate of 120 b.p.m. using one (S2) and two (S2,S3) premature stimuli. The data were analysed as to the presence ro absence of a repetitive ventricular response and the outcome of the patients ((1) sudden death less than or equal to 1 h or documented ventricular fibrilllation without myocardial infaction without myocardial infarction; (2) survivors or patients dying from non-cardiac or non-suddenly). A repetitive ventricular response was observed in 45/123 patients (36.6%) after one and in 51/120 patients (42.5%) after two premature stimuli. It occurred in 9/9 patients with ventricular fibrilation and in 20/23 patients (87%) with ventricular tachycardia. Mean follow-up period was 84 +/- 37.1 weeks (+/- S.D.). Five patients were lost to follow-up. 17/123 patients were classified as sudden death patients, the remaining patients were regarded as surviving (or dying non-suddenly). After one premature stimulus, a repetitive ventricular response was observed in 34.9% of survivors and in 47.1% of non-survivors (n.s.). After two premature stimuli, the incidence of a repetitive ventricular response increased from 36.8% in survivors to 70.6% in non-survivors (p less than 0.005). 12/106 of patients (11.3%) surviving and 10/17 patients (58.8%) non-surviving had more than three ventricular echo beats (p less than 0.005). All patients non-surviving who demonstrated a repetitive ventricular response has intraventricular reentry. Depending on the regidity of the criteria used (i.e. number of echo beats), the sensitivity of the test ranged between 47 to 88%, whereas the specificity ranged between 44 to 94%. The number of false-positives was high (43 to 80%); however, the number of false-negatives was low (4 to 8%). Concluding, this retrospective study has shown a correlation between sudden death and the incidence and number of repetitive ventricular response (depending on the number of premature stimuli) and the type of reentrant beats (bundle branch reentry or intraventricular reentry).